Fight over Craigslist exchange led to shooting, police say

Markham man charged with murder of Tinley Park resident

A deadly shooting outside a Tinley Park convenience store last week was fueled by an argument over a Craigslist transaction, according to authorities.

Christopher Dyson, 18, was charged with first-degree murder and armed robbery for allegedly shooting Thomas Mastro, 24, of Tinley Park, during a fight over an online gaming system outside a 7-Eleven convenience store around 3 p.m. March 21, prosecutors and police said.

Dyson and Mastro had agreed to meet at the store at 16658 S. Oak Park Ave., just blocks from Mastro's home, to swap Dyson's iPhone for Mastro's PlayStation video game console, prosecutors said Saturday at a hearing in Cook County Central Bond Court.

Dyson was ordered held without bond on the first-degree murder and robbery charges.

Surveillance video obtained by police shows Dyson putting a box with the gaming system into a Mercedes, then struggling with Mastro after Mastro went to retrieve the box from the car, Assistant State's Attorney Dan Calandriello said. Dyson allegedly pulled out a pistol and shot Mastro in the chest.

The Cook County medical examiner's office said Mastro died of a single gunshot wound to the chest.

Dyson, of the 16600 block of Winchester Avenue in Markham, fled the scene. A witness flagged down an off-duty Tinley Park police officer, who was in his marked, take-home squad car.

Dyson led the officer on a high-speed chase up Oak Park Avenue into Oak Forest, where he abandoned his car in the parking lot of a restaurant adjacent to a forest preserve. Dyson ran into the woods.

After a 45-minute manhunt that involved some 50 police officers, a half-dozen search dogs and police helicopter, Dyson was spotted coming out of the forest preserve. Two police officers chased him into the woods and took him into custody.

Police found a weapon near 159th Street and Oak Park Avenue, several blocks south of where Dyson ditched his car, Tinley Park police Cmdr. Steve Vaccaro said.

Mastro, who lived in the 6900 block of Coachwood Trail, was engaged to marry his longtime girlfriend, and had a 4-year-old son, said his father, Perry Mastro. "He was a good kid," his father said.